A prefilled syringe in which a liquid medicine is filled in advance has been used to prevent use of a wrong medical agent, prevent hospital infection, reduce waste, and increase efficiency in hospital service. Syringes including a syringe to be used as the prefilled syringe are constructed of an outer cylinder, a gasket slidable inside the syringe, and a plunger for operating the movement of the gasket respectively. To enhance the sliding performance of the gasket and obtain a high degree of flow accuracy without generating a large irregularity in the discharge of the liquid medicine from the syringe, silicone oil or the like is applied to a sliding portion of the outer surface of the gasket or the inner surface of the syringe as a lubricant. Depending on the kind of the liquid medicine, an interaction occurs between the liquid medicine and the lubricant such as the silicone oil. When the liquid medicine is stored for a long time after the liquid medicine is filled in the syringe, it is deteriorated by the interaction. Thus it is difficult to use some kinds of medical agents for the prefilled syringe.
It is desirable for the prefilled syringe that is stored for a long time with the medical agent solution being filled therein to keep the medical agent solution stable for a long time and eliminate the need for the use of the lubricant.
To address the above-described problem, as disclosed in patent document 1 (Japanese Patent Application Laid-Open No. 62-32970), patent document 2 (Japanese Patent Application Laid-Open No. 2002-089717), and patent document 3 (U.S. Pat. No. 7,111,848), prefilled syringes were proposed in which the surface of the gasket is covered with the fluorine resin which is a material having a lower friction coefficient than the material of the gasket body to eliminate the use of the lubricant.
The present applicant proposed the gasket having the coating layer composed of the fluorine resin, the silicon resin, and the urethane resin, as disclosed in a patent document 4 (Japanese Patent Application Laid-Open No. 2004-321614); and the gasket having the coating layer composed of the film made of the composition containing the sliding property-imparting component and the flexibility-imparting component and of the fine solid particles held by the film to form the rough surface on the gasket, as disclosed in patent document 5 (Japanese Patent Application Laid-Open No. 2006-167110) and patent document 6 (Japanese Patent Application Laid-Open No. 2008-287, U.S. Patent Application Publication No. 2007/0299402). As also disclosed in patent document 7 (WO Publication No. 2009-084646, U.S. Patent Application Publication No. 2010/0324501), the present applicant devised the composition containing the sliding property-imparting component, the flexibility-imparting component, and the adhesive component and proposed the gasket having the coating layer not containing the fine solid particles.
Patent document 1: Japanese Patent Application Laid-Open No. 62-32970
Patent document 2: Japanese Patent Application Laid-Open No. 2002-089717
Patent document 3: U.S. Pat. No. 7,111,848
Patent document 4: Japanese Patent Application Laid-Open No. 2004-321614
Patent document 5: Japanese Patent Application Laid-Open No. 2006-167110
Patent document 6: Japanese Patent Application Laid-Open No. 2008-287 (U.S. Patent Application Publication No. 2007/0299402)
Patent document 7: WO Publication No. 2009-084646 (U.S. Patent Application Publication No. 2010/0324501)